[78-L] Binaural, duophonic, etc.

[Royal Pemberton]

And wasn't Fairchild's 641 (I think that's the model) stereo cutter built on
a lateral/vertical design, although with proper treatment of signals, would
produce stereo discs suited for 45/45 stereo playback?

I remember seeing an article in either Radio-Electronics or Radio & TV News
circa 1957 that explained a compatible stereo cutting system designed by
Jerry Minter of Components Corporation whose record masters could be cut
with an ordinary lateral mono cutter; it was in a sense a precursor of the
technique behind CD-4 quad records in that the sum signal was cut in the
conventional manner whilst the difference signal was FM modulated with an
ultrasonic signal.  High quality wideband pickups and preamps were required
to recover all the information from the records and reconstruct proper left
and right channels.

On Thu, Apr 21, 2011 at 9:08 PM, Michael Biel <mbiel at mbiel.com> wrote:

> On 4/21/2011 2:40 PM, Steve Williams wrote:
> > Mike Biel is correct.  I was referring to the Blumlein "Matrixed" method
> of
> > using a unidirectional wide pattern cardoid facing forwards, which is
> summed
> > with the left-pointing cardoid and subtracted from the right-pointing mic
> -
> > Or something like that.. :-)
>
> I believe that some of the experiments were recording the front mic on
> one track and the sidewards mic on the other track and doing the
> matrixing on playback.  OR you could do the matrixing before recording
> and record the left on one track and right on the other.  See what I
> also say below.
>
> >   But anyway David is right, that is not a
> > correct method of capturing accurate "two-ear" imaging but can provide
> > exceptionally realistic sound for playback on two speakers.  (I was at
> work
> > and typing hastily.) When referring to Binaural, Stereo etc. I was going
> by
> > current-day understanding of their meaning, I realize the terms were used
> > differently in the past.
> >
>
> David mentioned that coincidental pair systems of miking give no time
> displacement clues to the brain, only level differences.  The brain
> needs both for binaural (using the modern meaning of the word.)  (I
> think we are losing a lot of our audience here with all this geekiness!!)
>
> > I have the 1952 Mercury Wilbur DeParis Cook "Binaural" LP, and wonder how
> on
> > earth anyone expected to get proper results using a twin spiral.
>
>
> You mean Atlantic, don't you?  If so, I have this too, along with a real
> single groove stereo issue of the recordings that Atlantic issued in the
> late 50s.
>
> >   (Many many
> > years ago I stumbled upon a hoarder-of-anything who happened to have a
> NIB
> > Cook arm among his detritus.  I begged and pleaded to get it from him,
> who
> > didn't even know what it was, to no avail.)
>
> That is closer than I have ever gotten to a Cook binaural arm.
>
> >   But regardless, having two
> > channels is just the start of the equation; most critical is that
> accurate
> > timing of the two channels is necessary to maintain accurate phasing to
> > preserve the imaging used by the ear to judge direction and distance of
> the
> > source.  All early forms of record-playback equipment, except multitrack
> > film, could not preserve that accuracy.
>
> I would really like to have a cook arm to see how much the phasing would
> be affected by the traxcking era that must occur with that arm.  I would
> assume that Cook cut his masters with a normal straight-line lathe which
> would maintain accurate syncing of the two tracks ONLY if played back on
> a similar straight-line arm like a Rabco -- and no dual head arm like
> that was ever made.  Of course it IS possible that Cook had a special
> RADIAL cutting arm with the two cutting heads which would match the
> tracking era of the playback arm.  I've never seen anybody discuss this,
> especially Cook.
>
> Most early miltitrack film equipment recorded the different tracks on
> separate films.  Because film is sprocketed it does not slip like tape
> can.  The recorders are synchronized with locked three-phase motors
> which also does not allow slippage.  (Once locked, if you turn the motor
> shaft of one and the others will also turn!)   In playback and editing
> the films can be passed thru synchronizers which are multiple sprocket
> wheels on one shaft.  The picture film is also synced this way.  By the
> 1950s most multitrack optical or magnetic film were recorded on one
> film, but of course they still have to be synced with the separate
> picture film.
>
> > Even early CD players which used
> > only one DA convertor were anathema to Golden ears who could detect the
> > timing error introduced between the two channels.
>
> Most people don't realize that there is only one digital stream on CDs
> with the samples of the left and right tracks interlaced.
>
> >   Staggered-head tape
> > machines were getting there, but still fussy, until finally stacked audio
> > heads and single-track record cutting were developed.
>
> Right.  There can be spacing irregularities between the two heads, and
> tape stretching or shrinkage will also mess it up.
>
> >   I guess the Decca
> > vertical-Horizontal matrixed method of cutting was similar to the
> Blumlein
> > matrixed mic pickups, and FM radio with the AM sideband subcarrier
> providing
> > the difference signal to the FM summed channel.
> >
> > Steve Williams..
> >
>
> Both Blumlein and Western Electric experimented with vertical-lateral
> single groove stereo.  I believe -- but do not know for sure -- that it
> can be played back with a standard 45-45 stereo cartridge.  I don't
> remmber how these different companies experimented with having the two
> directions being the discrete left and right signals, or which had the
> lateral be the sum of both with the vertical being the difference.  I'd
> have to pull out a whole bunch of books and articles to remember all of
> this!
> Pearl had sold pressings made from Blumlein masters, but I was not able
> to buy some in time.  Anybody here have them?
>
> Mike Biel  mbiel at mbiel.com
>
>
>
> > Date: Wed, 20 Apr 2011 14:02:08 -0700 (PDT)
> > From: DAVID BURNHAM<burnhamd at rogers.com>
> > Subject: [78-L] Binaural, duophonic, etc.
> > To: 78-L at 78online.com
> > Message-ID:<414652.32411.qm at web88103.mail.re2.yahoo.com>
> > Content-Type: text/plain; charset=us-ascii
> >
> > Dan Van Landingham wrote:
> >
> > "Binaural" refers to a method of recording that mimics the human
> > ear. - "Two Sounds." The microphones are literally mounted on a Styrofoam
> > head in some cases, or a single crossed-8 cardoid stereo mic is used.
>  The
> > listener wears headphones.
> >
> > ~~~~~~~~~~~~~~~~~~~
> >
> > As dl has pointed out, Duophonic was a Capitol term for simulated stereo.
> >   Binaural recordings have to be made using microphones spaced
> approximately
> > the
> > same distance apart as the distance between a pair of ears, just like
> stereo
> >
> > photography uses two cameras which are eye-spaced apart.  In both cases
> the
> > signal for the left ear/eye cannot reach the right ear/eye or it won't
> work.
> >
> >   That's why headphones or some sort of glasses must be employed
> respectively
> >
> > BUT the second half of the above statement is not only wrong, but is
> > confusing.
> >   There are several different kinds of mikes, based on polar patterns;
>  two
> > of
> > these are Cardioid and figure of 8.  Crossed figure of 8, (or
> bidirectional)
> >
> > mics will yield superb stereo recordings reproduced on speakers.  This is
> > known
> > as an XY system and was regularly used by BBC and EMI in the early days
> of
> > Stereo.  The system was invented by Alan Blumlein and bears his name.  A
> > bidirectional mike is also known as a cosine mike because the level of
> > pickup is
> > proportional to the cosine of the angle of incidence on the mike.  This
> may
> > sound confusing but what it means is that this particular pickup is ideal
> > because when your position to the mike is 90 degrees, which in an XY
> system
> > is
> > the direction from which the right signal will be arriving to the left
> > channel
> > mike, the output is theoretically zero, (the cosine of 90 degrees is
> "0").
> > At
> > 45 degrees, which is the angle at which each mike will be picking up a
> > centre
> > sound source, the output of each mike is reduced by half.  If a speaker
> > walks
> > from the extreme left to the extreme right of an XY pair of figure 8s,
> his
> > voice
> > level will not vary and the direction of the image will be identical to
> his
> > position on the sound stage.
> >
> > Crossed cardioids, on the other hand, produce a less than ideal stereo
> > image.  A
> > cardioid mike is only down a couple of dBs at 90 degrees so a signal from
> > the
> > right side of the sound stage will produce a considerable signal to the
> left
> >
> > channel mike.  If the same speaker walks across a XY pair of cardioid
> mikes,
> > the
> > image will never be at the extreme left or right and the voice will be
> > louder
> > when he is at the centre, (called centre channel build up).
> >
> > In any case, neither of these situations will produce binaural recordings
> > because the inter-channel time difference which is required for binaural
> > reproduction is totally absent when using a coincident stereo mike.
> >
> > db
> >
> > ------------------------------
> >
> > Message: 9
> > Date: Wed, 20 Apr 2011 19:26:35 -0400
> > From: Michael Biel<mbiel at mbiel.com>
> > Subject: Re: [78-L] Binaural, duophonic, etc.
> > To: 78-L Mail List<78-l at klickitat.78online.com>
> > Message-ID:<4DAF6BAB.7040701 at mbiel.com>
> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> >
> > On 4/20/2011 5:02 PM, DAVID BURNHAM wrote:
> >> Dan Van Landingham wrote:
> >>
> >> "Binaural" refers to a method of recording that mimics the human
> >> ear. - "Two Sounds." The microphones are literally mounted on a
> Styrofoam
> >> head in some cases,
> > Let me mention again that this use of the word was not solidified until
> > the 1960s.  Prior to this binaural was used for just about any
> > two-channel recording, including some that have w-i-d-e separation.
> >
> >>    or a single crossed-8 cardoid stereo mic is used.  The
> >> listener wears headphones.
> >>
> > The explanation below is quite good, but I think that the above
> > description might have been mis-understood because the wording is a
> > little confusing.  Blumlein and others didn't always use a pair of
> > bi-directional with one facing forward and the other facing sidewards.
> > Sometimes a cardioid is used facing forward and the bi-directional
> > pattern is facing sidewards.  I think this is what is meant in this
> > description.  Using a cardioid as the forward facing mic instead of a
> > bi-directional reduces pickup from the rear, such as audience noise and
> > hall reverberation.   Stereo mics like the AKG C-24allowed for the
> > changing of the patterns -- in the case of the C-24 even from the
> > control room while listening to the results live!
> >
> > Mike Biel  mbiel at mbiel.com
> >> ~~~~~~~~~~~~~~~~~~~
> >
> > _______________________________________________
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> >
> >
>
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